Battery pack and method of assembling the battery pack

ABSTRACT

A battery pack having a battery pack housing defining an interior region is provided. The housing further includes an inlet aperture and an outlet aperture communicating with the interior region. The battery pack further includes a battery module that is disposed in the interior region of the battery pack housing proximate to the inlet aperture. The battery module has a first battery cell, a heat exchanger, and first and second end plates. The first battery cell and the heat exchanger are disposed against one another, and are further disposed between the first and second end plates. The heat exchanger defines a first flow path portion therethrough. The first end plate has a first end portion that extends longitudinally past the first end of the first battery cell, and a second end portion that extends longitudinally past the second end of the first battery cell.

BACKGROUND

The inventors herein have recognized a need for an improved battery pack and a method of assembling the battery pack.

SUMMARY

A battery pack in accordance with an exemplary embodiment is provided. The battery pack includes a battery pack housing defining an interior region. The battery pack housing further includes an inlet aperture and an outlet aperture communicating with the interior region. The battery pack further includes a battery module that is disposed in the interior region of the battery pack housing proximate to the inlet aperture. The battery module has a first battery cell, a heat exchanger, and first and second end plates. The first battery cell and the heat exchanger are disposed against one another, and are further disposed between the first and second end plates. The heat exchanger defines a first flow path portion therethrough. The first battery cell has a first end and a second end. The first end plate extends substantially parallel to a longitudinal axis of the battery module toward the inlet aperture. The first end plate has a first end portion and a second end portion. The first end portion of the first end plate extends longitudinally past the first end of the first battery cell. The second end portion of the first end plate extends longitudinally past the second end of the first battery cell. The second end plate extends substantially parallel to the longitudinal axis of the battery module. The second end plate has a first end portion and a second end portion. The first end portion of the second end plate extends longitudinally past the first end of the first battery cell toward the inlet aperture. The second end portion of the second end plate extends longitudinally past the second end of the first battery cell. The battery pack further includes a thermally conductive housing that is disposed in the interior region of the battery pack housing between the battery module and the outlet aperture of the battery pack housing. The thermally conductive housing defines a second flow path portion between the thermally conductive housing and the battery pack housing. The second flow path portion fluidly communicates with the first flow path portion. The battery pack further includes an electric fan disposed in the interior region of the battery pack housing. The electric fan is adapted to urge air to flow through the inlet aperture and through the first and second flow path portions and further through a portion of the electric fan and through the outlet aperture of the battery pack housing.

A method for assembling a battery pack in accordance with another exemplary embodiment is provided. The method includes providing a battery pack housing, a battery module, a thermally conductive housing, and an electric fan. The battery pack housing defines an interior region. The battery pack housing further includes an inlet aperture and an outlet aperture communicating with the interior region. The battery module has a first battery cell, a heat exchanger, and first and second end plates. The first battery cell and the heat exchanger are disposed against one another, and are further disposed between the first and second end plates. The heat exchanger defines a first flow path portion therethrough. The first battery cell has a first end and a second end. The first end plate extends substantially parallel to a longitudinal axis of the battery module. The first end plate has a first end portion and a second end portion. The first end portion of the first end plate extends longitudinally past the first end of the first battery cell. The second end portion of the first end plate extends longitudinally past the second end of the first battery cell. The second end plate extends substantially parallel to the longitudinal axis of the battery module. The second end plate has a first end portion and a second end portion. The first end portion of the second end plate extends longitudinally past the first end of the first battery cell. The second end portion of the second end plate extends longitudinally past the second end of the first battery cell. The method further includes disposing the battery module in the interior region of the battery pack housing proximate to the inlet aperture. The method further includes disposing the thermally conductive housing in the interior region of the battery pack housing between the battery module and the outlet aperture of the battery pack housing. The thermally conductive housing defines a second flow path portion between the thermally conductive housing and the battery pack housing. The second flow path portion fluidly communicates with the first flow path portion. The method further includes disposing the electric fan in the interior region of the battery pack housing. The electric fan is adapted to urge air to flow through the inlet aperture and through the first and second flow path portions and further through a portion of the electric fan and through the outlet aperture of the battery pack housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a battery pack in accordance with an exemplary embodiment;

FIG. 2 is another schematic of the battery pack of FIG. 1;

FIG. 3 is a partially transparent top view of the battery pack of FIG. 1;

FIG. 4 is a partially transparent bottom view of the battery pack of FIG. 1;

FIG. 5 is a schematic of a base portion of a battery pack housing utilized in the battery pack of FIG. 1;

FIG. 6 is a cross-sectional schematic of the battery pack of FIG. 1;

FIG. 7 is a schematic of a battery module utilized in the battery pack of FIG. 1;

FIG. 8 is another schematic of the battery module of FIG. 7;

FIG. 9 is a cross-sectional schematic of the battery module of FIG. 7 taken along lines 9-9;

FIG. 10 is a cross-sectional schematic of the battery module of FIG. 7 taken along lines 10-10;

FIG. 11 is an exploded view of a portion of the battery module of FIG. 7;

FIG. 12 is a schematic of a first side of the battery module of FIG. 7 illustrating ends of first, second, and third heat exchangers;

FIG. 13 is a schematic of a second side of the battery module of FIG. 7 illustrating ends of first, second, and third heat exchangers;

FIG. 14 is a schematic of a frame member utilized in the battery module of FIG. 7;

FIG. 15 is another schematic of the frame member of FIG. 14;

FIG. 16 is another schematic of the frame member of FIG. 15;

FIG. 17 is a side view of the frame member of FIG. 15 illustrating an end of a heat exchanger;

FIG. 18 is a schematic of a first side of the frame member of FIG. 15;

FIG. 19 is a schematic of a second side of the frame member of FIG. 15;

FIG. 20 is a schematic of a first side of a first thermally conductive plate utilized in a heat exchanger in the frame member of FIG. 15;

FIG. 21 is a schematic of a second side of the first thermally conductive plate of FIG. 20;

FIG. 22 is a schematic of a first side of a second thermally conductive plate utilized in a heat exchanger in the frame member of FIG. 15;

FIG. 23 is a schematic of a thermally conductive housing utilized in the battery pack of FIG. 1;

FIG. 24 is another schematic of the thermally conductive housing of FIG. 23;

FIG. 25 is a schematic of a bottom side of the thermally conductive housing of FIG. 23;

FIG. 26 is another schematic of the thermally conductive housing of FIG. 23;

FIG. 27 is a flowchart of a method of assembling a battery module in accordance with another exemplary embodiment; and

FIG. 28 is a flowchart of a method of assembling a battery pack in accordance with another exemplary embodiment.

DETAILED DESCRIPTION

Referring to FIGS. 1-6, a battery pack 10 in accordance with an exemplary embodiment is provided. The battery pack 10 includes a battery pack housing 30, a battery module 34, a thermally conductive housing 38, a DC/DC voltage converter 42, and an electric fan 46. An advantage of the battery pack 10 is that the battery pack 10 has the battery module 34 with end plates 230, 232 that extend past internal battery cells to direct air into heat exchangers contacting the battery cells. Thus, the battery pack 10 does not need a separate air manifold to direct air into heat exchangers contacting the battery cells.

Referring to FIGS. 1, 2 and 5, the battery pack housing 30 is provided to hold the remaining components of the battery pack 10 therein. The battery pack housing 30 has a base portion 70 and an upper cover 72 which define an interior region 74. The interior region 74 includes an interior space 76 and an interior space 78.

Referring to FIG. 5, the base portion 70 includes a bottom wall 90 and side walls 92, 94, 96, 98. The side walls 92, 94, 96, 98 are coupled to the bottom wall 90 and extend upwardly substantially perpendicular to the bottom wall 90. The side walls 92, 94 extend substantially parallel to one another. Further, the side walls 96, 98 extend substantially parallel to one another and perpendicular to the side walls 92, 94. The side wall 92 includes an inlet aperture 112 extending therethrough, and the side wall 94 includes an outlet aperture 114 extending therethrough. In an exemplary embodiment, the base portion 70 is constructed of steel or aluminum. In an alternative embodiment, the base portion 70 is constructed of plastic.

The upper cover 72 is removably coupled to the side walls 92, 94, 96, 98 to enclose the interior region 74. In an exemplary embodiment, the upper cover 72 is constructed of steel or aluminum. In an alternative embodiment, the upper cover 72 is constructed of plastic.

Referring to FIGS. 5-11, the battery module 34 is disposed in the interior space 76 of the interior region 74 of the battery pack housing 30 proximate to the inlet aperture 112. The battery module 34 includes frame members 120, 124, 128, an insulating layer 140, battery cells 150, 154, 158, 162, 166, 170, 180, 184, 188, 192, 196, 200, battery cell interconnect assemblies 220, 222, and end plates 230, 232.

Referring to FIGS. 7, 9, and 10, the frame members 120, 124, 128 are provided to hold the battery cells 150-200 therebetween. The frame member 124 is coupled to and between the frame members 120, 128. The structure of each of the frame members 120, 124, 128 are identical to one another. Accordingly, only the structure of the frame member 120 will be described in detail below.

Referring to FIGS. 14-21, the frame member 120 has a substantially rectangular ring-shaped outer plastic frame 260, central plastic walls 262, 263, and a heat exchanger 264. The heat exchanger 264 has first and second thermally conductive plates 360, 362 that are coupled together and define a flow path portion 540 that extends therethrough. Referring to FIG. 17, the flow path portion 540 has flow path subportions 550, 552, 554, 556, 558, 560 each extending through the first and second thermally conductive plates 360, 362.

Referring to FIGS. 14-16, the substantially rectangular ring-shaped outer plastic frame 260 is coupled around an outer peripheral region of the first and second thermally conductive plates 360, 362. The first substantially rectangular ring-shaped outer plastic frame 360 has first, second, third, and fourth side walls 280, 282, 284, 286. The first and second side walls 280, 282 extend substantially parallel to one another. The third and fourth side walls 284, 286 are coupled between the first and second side walls 280, 282 and extend substantially parallel to one another and perpendicular to the first and second side walls 280, 282.

The central plastic wall 262 extends between the third and fourth side walls 284, 286 substantially parallel to the first and second side walls 280, 282. The central plastic wall 262 is disposed on a portion of the first side 380 (shown in FIG. 20) of the thermally conductive plate 360 of the heat exchanger 264.

The central plastic wall 263 extends between the third and fourth side walls 284, 286 substantially parallel to the first and second side walls 280, 282. The central plastic wall 263 is disposed on a portion of the first side 480 (shown in FIG. 22) of the thermally conductive plate 362 of the heat exchanger 264.

The first, third, and fourth side walls 280, 284, 286 and the central plastic wall 262 define a region for receiving a battery cell therein. The second, third, and fourth side walls 282, 284, 286 define a region for receiving another battery cell therein.

The first side wall 280 has apertures 300, 302, 304 extending therethrough. The aperture 300 fluidly communicates with the flow path subportions 550, 552. Also, the aperture 302 fluidly communicates with the flow path subportions 554, 556. Further, the aperture 304 fluidly communicates with the flow path subportions 558, 560.

Referring to FIG. 17, the second side wall 282 has apertures 310, 312, 314 extending therethrough. The aperture 310 fluidly communicates with the flow path subportions 550, 552. Also, the aperture 312 fluidly communicates with the flow path subportions 554, 556. Further, the aperture 314 fluidly communicates with the flow path subportions 558, 560.

Referring to FIGS. 14 and 15, the third side wall 284 has grooves 320, 322, 324, 326 extending therein. The fourth side wall 286 has grooves 330, 332, 334, 336 extending therein. The grooves 320, 330 are configured to receive first and second electrical terminals of a battery cell therethrough. Further, the grooves 324, 334 are configured to receive first and second electrical terminals of another battery cell therethrough. Still further, the grooves 322, 332 are configured to receive first and second electrical terminals of another battery cell therethrough. Finally, the grooves 326, 336 are configured to receive first and second electrical terminals of another battery cell therethrough.

Referring to FIGS. 20-22, the heat exchanger 264 includes first and second thermally conductive plates 360, 362 that are coupled together and define the flow path portion 540 extending completely through the plates 360, 362.

The first thermally conductive plate 360 includes a sheet portion 370 having a first side 380 and a second side 382. The sheet portion 370 includes elongated depressed portions 390, 392, 394, 396, 398, 400, 402, 404, 406, 408, and depressed edge portions 410, 412. In an exemplary embodiment, the sheet portion 370 is constructed of aluminum and is substantially rectangular-shaped.

The second thermally conductive plate 362 includes a sheet portion 470 having a first side 480 and a second side 482. The sheet portion 470 includes elongated depressed portions 490, 492, 494, 496, 498, 500, 502, 504, 506, 508, and depressed edge portions 510, 512. In an exemplary embodiment, the sheet portion 470 is constructed of aluminum and is substantially rectangular-shaped.

The first thermally conductive plate 360 is coupled to the second thermally conductive plate 362 such that the elongated depressed portions 390, 392, 394, 396, 398, 400, 402, 404, 406, 408 contact and are coupled to the elongated depressed portions 490, 492, 494, 496, 498, 500, 502, 504, 506, 508, respectively and the depressed edge portions 410, 412 contact and are coupled to the depressed edge portions 510, 512. The plates 360, 362 define the flow path portion 540 having the flow path subportions 550, 552, 554, 556, 558, 560 that extending entirely through a longitudinal length of the plates 360, 362.

Referring to FIG. 7, the frame member 124 has an identical structure as the frame member 120 described above. The frame member 124 has a substantially rectangular ring-shaped outer plastic frame 570, first and second central plastic walls (not shown), and a heat exchanger 572.

The frame member 128 has an identical structure as the frame member 120 described above. The frame member 128 has a substantially rectangular ring-shaped outer plastic frame 580, first and second central plastic walls (not shown), and a heat exchanger 582.

Referring to FIGS. 6, 9 and 10, the frame member 120 and the end plate 232 are configured to hold the battery cells 150, 180 therebetween. Further, the heat exchanger 264 of the frame member 120 is disposed between and contacts the battery cells 150, 154. Also, the heat exchanger 264 is disposed between and contacts the battery cells 180, 184.

The frame members 120, 124 are configured to hold the battery cells 154, 158 therebetween. Further, the frame members 120, 124 are configured to hold the battery cells 184, 188 therebetween. The heat exchanger 572 of the frame member 124 is disposed between and contacts the battery cells 158, 162. Also, the heat exchanger 572 is disposed between and contacts the battery cells 188, 192.

The frame members 124, 128 are configured to hold the battery cells 162, 166 therebetween. Further, the frame members 124, 128 are configured to hold the battery cells 192, 196 therebetween. The heat exchanger 582 of the frame member 128 is disposed between and contacts the battery cells 166. 170. Also, the heat exchanger 582 is disposed between and contacts the battery cells 196, 200.

The frame member 128 and the insulating layer 140 (shown in FIG. 9) are configured to hold the battery cells 170, 200 therebetween. The heat exchanger 582 of the frame member 128 is disposed against the battery cells 170, 200. The end plate 230 is coupled to the frame member 128 such that the insulating layer 140 is disposed between the frame member 128 and the battery cells 170, 200.

The battery cells 150, 154, 158, 162, 166, 170, 180, 184, 188, 192, 196, 200 are each configured to generate an operational voltage. In one exemplary embodiment, the battery cells 150-200 are pouch-type lithium-ion battery cells that have a substantially rectangular-shaped body portion and a pair of electrical terminals. In an exemplary embodiment, the battery cells 150-200 are electrically coupled in series with one another utilizing interconnect members on the battery cell interconnect and voltage sensing assemblies 220, 222. Further, in an exemplary embodiment, the electrical terminals of the battery cells 150-200 are coupled to corresponding interconnect members by ultrasonically welding the electrical terminals of the battery cells 150-200 to the corresponding interconnect members utilizing an ultrasonic welding machine. The structure of the battery cells 150-200 are identical to one another.

Referring to FIG. 9, the battery cell 150 has a rectangular-shaped housing 640 with electrical terminals 642, 644, extending from first and second ends, respectively, of the housing 640. The electrical terminal 642 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 644 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 154 has a rectangular-shaped housing 650 with electrical terminals 652, 654, extending from first and second ends, respectively, of the housing 650. The electrical terminal 652 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 654 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 158 has a rectangular-shaped housing 660 with electrical terminals 662, 664, extending from first and second ends, respectively, of the housing 660. The electrical terminal 662 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 664 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 162 has a rectangular-shaped housing 670 with electrical terminals 672, 674, extending from first and second ends, respectively, of the housing 670. The electrical terminal 672 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 674 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 166 has a rectangular-shaped housing 680 with electrical terminals 682, 684, extending from first and second ends, respectively, of the housing 680. The electrical terminal 682 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 684 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 170 has a rectangular-shaped housing 690 with electrical terminals 692, 694, extending from first and second ends, respectively, of the housing 690. The electrical terminal 692 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 694 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The series combination of the battery cells 150-170 are electrically coupled in series with the series combination of the battery cells 180-200 utilizing an elongated interconnect member.

Referring to FIG. 10, the battery cell 180 has a rectangular-shaped housing 700 with electrical terminals 702, 704 extending from first and second ends, respectively, of the housing 700. The electrical terminal 702 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 704 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 184 has a rectangular-shaped housing 710 with electrical terminals 712, 714 extending from first and second ends, respectively, of the housing 710. The electrical terminal 712 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 714 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 188 has a rectangular-shaped housing 720 with electrical terminals 722, 724 extending from first and second ends, respectively, of the housing 720. The electrical terminal 722 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 724 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 192 has a rectangular-shaped housing 730 with electrical terminals 732, 734 extending from first and second ends, respectively, of the housing 730. The electrical terminal 732 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 734 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 196 has a rectangular-shaped housing 740 with electrical terminals 742, 744 extending from first and second ends, respectively, of the housing 740. The electrical terminal 742 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 744 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

The battery cell 200 has a rectangular-shaped housing 750 with electrical terminals 752, 754 extending from first and second ends, respectively, of the housing 750. The electrical terminal 752 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 220. The electrical terminal 754 is electrically and physically coupled to the battery cell interconnect and voltage sensing assembly 222.

Referring to FIG. 6, the end plates 230, 232 are provided to guide cooling air through the flow path portions 540, 574, 584 of the frame members 120, 124, 128, respectively. The end plates 230, 232 have the frame members 120-128 and the battery cells 150-200 disposed therebetween.

The end plate 230 extends substantially parallel to a longitudinal axis 768 of the battery module 34. The end plate 230 has a first end portion 770 and a second end portion 772. The first end portion 770 extends longitudinally past a first end of each of the battery cells 150-170 toward the inlet aperture 112. The second end portion 772 extends longitudinally past the second end of each of the battery cells 180-200.

The end plate 232 extends substantially parallel to the longitudinal axis 768 of the battery module 34. The end plate 232 has a first end portion 780 and a second end portion 782. The first end portion 780 extends longitudinally past a first end of each of the battery cells 150-170 toward the inlet aperture 112. The second end portion 782 extends longitudinally past the second end of each of the battery cells 180-200.

Referring to FIGS. 5, 6 and 23-26, the thermally conductive housing 38 is provided to hold the DC/DC voltage converter 42 therein that is electrically coupled to the battery cells of the battery module 34. The thermally conductive housing 38 transfers heat from the DC/DC voltage converter 42 to air flowing past the thermally conductive housing. The thermally conductive housing 38 is disposed in the interior space 78 of the interior region 74 of the battery pack housing 30 between the battery module 34 and the outlet aperture 114 of the battery pack housing 30. The thermally conductive housing 38 defines a flow path portion 804 between the thermally conductive housing 38 and the battery pack housing 30. The flow path portion 804 fluidly communicates with the flow path portions 540, 574, 584 of the battery module 34 and with the outlet aperture 114.

The thermally conductive housing 38 includes a housing portion 800 and a frame member 802. The housing portion 800 includes bottom wall 810 and cooling fins 820, 822, 824, 826, 840, 842, 844, 846, 848 extending outwardly from the bottom wall 810 in a first direction. The cooling fins 820-848 are spaced apart from one another such that the flow path portion 804 is defined between the cooling fins 820-848. The cooling fins 820-848 are disposed on the bottom wall 90 (shown in FIG. 5) of the base portion 70. In an exemplary embodiment, the thermally conductive housing 38 is constructed of aluminum. Of course, in an alternative embodiment, the thermally conductive housing 38 can be constructed of other materials such as steel or other metal alloys for example.

Referring to FIGS. 6 and 23, the frame member 802 is coupled to an exterior of the thermally conductive housing 38 and includes an outlet portion 870 that directs air toward the fan 46 and the outlet aperture 114 of the battery pack housing 30.

Referring to FIGS. 5 and 6, the electric fan 46 is disposed in the interior region 74 of the battery pack housing 30 proximate to the outlet aperture 114 of the battery pack housing 30. The electric fan 46 is adapted to urge air to flow through the inlet aperture 112 and through the flow path portions 540, 574, 584 of the battery module and the flow path portion 804 and further through a portion of the electric fan 46 and through the outlet aperture 114 of the battery pack housing 30. In an alternative embodiment, the electric fan 46 is disposed proximate to the inlet aperture 112.

Referring to FIGS. 6, 14, 16, 17 and 27, a flowchart of a method of assembling a portion of the battery module 34 in accordance with another exemplary embodiment is provided.

At step 900, a user provides the battery cells 154, 184. After step 900, the method advances to step 902.

At step 902, the user provides the frame member 120 having the substantially rectangular ring-shaped outer plastic frame 260 and the heat exchanger 264. The heat exchanger 264 has first and second thermally conductive plates 360, 362 that are coupled together and define a flow path portion 540 (shown in FIG. 17) extending therethrough. The flow path portion 540 has at least flow path subportions 554, 558 extending through the first and second thermally conductive plates 360, 362. The substantially rectangular ring-shaped outer plastic frame 260 is coupled around an outer peripheral region of the first and second thermally conductive plates 360, 362. The substantially rectangular ring-shaped outer plastic frame 260 has first, second, third, and fourth side walls 280, 282, 284, 286. The first and second side walls 280, 282 extend substantially parallel to one another. The third and fourth side walls 284, 286 are coupled between the first and second side walls 280, 282 and extend substantially parallel to one another and perpendicular to the first and second side walls 280, 282. The first side wall 280 has apertures 302, 304 (shown in FIG. 14) extending therethrough that communicate with the flow path subportions 554, 558, respectively. The second side wall 282 has apertures 312, 314 (shown in FIG. 17) extending therethrough that communicate with the flow path subportions 554, 558, respectively. After step 902, the method advances to step 904.

At step 904, the user disposes the battery cell 154 on and against a first side of the first thermally conductive plate 360 of the heat exchanger 264. After step 904, the method advances to step 906.

At step 906, the user disposes the battery cell 184 on and against the first side of the first thermally conductive plate 360 of the heat exchanger 264. The battery cell 184 is further disposed proximate to the battery cell 154. After step 906, the method advances to step 908.

At step 908, the user provides battery cells 158, 188 and the frame member 124 having the heat exchanger 572. After step 908, the method advances to step 910.

At step 910, the user disposes the battery cell 158 on and against the battery cell 154. After step 910, the method advances to step 912.

At step 912, the user disposes the battery cell 188 on and against the battery cell 184. After step 912, the method advances to step 914.

At step 914, the user disposes the heat exchanger 572 on the battery cells 158, 188.

Referring to FIGS. 2, 6 and 28, a flowchart of a method of assembling the battery pack 10 in accordance with another exemplary embodiment is provided.

At step 930, the user provides the battery pack housing 30, the battery module 34, the thermally conductive housing 38, and the electric fan 46. The battery pack housing 30 defines the interior region 74. The battery pack housing 30 further includes the inlet aperture 112 and the outlet aperture 114 communicating with the interior region 74. The battery module 34 has the battery cell 154, the heat exchanger 264, and end plates 230, 232. The battery cell 154 and the heat exchanger 264 are disposed against one another, and are further disposed between the end plates 230, 232. The heat exchanger 264 defines a flow path portion 540 therethrough. The battery cell 154 has a first end and a second end. The end plate 230 extends substantially parallel to the longitudinal axis 768 of the battery module 34. The end plate 230 has the first end portion 770 and the second end portion 772. The first end portion 770 of the end plate 230 extends longitudinally past the first end of the battery cell 154. The second end portion 772 of the end plate 230 extends longitudinally past the second end of the battery cell 154. The end plate 232 extends substantially parallel to the longitudinal axis 768 of the battery module 34. The end plate 232 having the first end portion 780 and the second end portion 782. The first end portion 780 of the end plate 232 extends longitudinally past the first end of the battery cell 154. The second end portion 782 of the end plate 232 extends longitudinally past the second end of the battery cell 154. After step 930, the method advances to step 932.

At step 932, the user disposes the battery module 34 in the interior region 74 of the battery pack housing 30 proximate to the inlet aperture 112. After step 932, the method advances to step 934.

At step 934, the user disposes the thermally conductive housing 38 in the interior region 74 of the battery pack housing 30 between the battery module 34 and the outlet aperture 114 of the battery pack housing 30. The thermally conductive housing 38 defines the path portion 804 between the thermally conductive housing 38 and the battery pack housing 30. The flow path portion 804 fluidly communicates with the flow path portion 540. After step 934, the method advances to step 936.

At step 936, the user disposes the electric fan 46 in the interior region 74 of the battery pack housing 30 proximate to the outlet aperture 114 of the battery pack housing 30. The electric fan 46 is adapted to urge air to flow through the inlet aperture 112 and through the path portions 540, 804 and further through a portion of the electric fan 46 and through the outlet aperture 114 of the battery pack housing 30.

The battery pack and the method of assembling the battery pack provide a substantial advantage over other battery packs and methods. In particular, the battery pack and the method utilize a battery module with first and second end plates that extend past ends of a battery cell to direct air into a heat exchanger disposed against the battery cell to cool the battery module.

While the claimed invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the claimed invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the claimed invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the claimed invention is not to be seen as limited by the foregoing description. 

What is claimed is:
 1. A battery pack, comprising: a battery pack housing defining an interior region, the battery pack housing further having an inlet aperture and an outlet aperture communicating with the interior region; a battery module being disposed in the interior region of the battery pack housing proximate to the inlet aperture, the battery module having a first battery cell, a heat exchanger, and first and second end plates; the first battery cell and the heat exchanger being disposed against one another, and being further disposed between the first and second end plates; the heat exchanger defining a first flow path portion therethrough; the first battery cell having a first end and a second end; the first end plate extending substantially parallel to a longitudinal axis of the battery module, the first end plate having a first end portion and a second end portion, the first end portion of the first end plate extending longitudinally past the first end of the first battery cell toward the inlet aperture; the second end portion of the first end plate extending longitudinally past the second end of the first battery cell; the second end plate extending substantially parallel to the longitudinal axis of the battery module, the second end plate having a first end portion and a second end portion, the first end portion of the second end plate extending longitudinally past the first end of the first battery cell toward the inlet aperture; the second end portion of the second end plate extending longitudinally past the second end of the first battery cell; a thermally conductive housing being disposed in the interior region of the battery pack housing between the battery module and the outlet aperture of the battery pack housing; the thermally conductive housing defining a second flow path portion between the thermally conductive housing and the battery pack housing, the second flow path portion communicating with the first flow path portion; and an electric fan disposed in the interior region of the battery pack housing; the electric fan adapted to urge air to flow through the inlet aperture and through the first and second flow path portions and further through a portion of the electric fan and through the outlet aperture of the battery pack housing.
 2. The battery pack of claim 1, wherein the battery pack housing has a base portion and an upper cover; the base portion and the upper cover defining the interior region when the upper cover is coupled to the base portion, the thermally conductive housing having a bottom wall and a plurality of cooling fins extending outwardly from the bottom wall and spaced apart from one another such that the second flow path portion is at least partially defined between the plurality of cooling fins.
 3. The battery pack of claim 2, wherein the thermally conductive housing holds a DC/DC voltage converter that is electrically coupled to the first battery cell of the battery module.
 4. The battery pack of claim 3, wherein the base portion of the battery pack housing includes a bottom wall, the battery module being disposed on the bottom wall of the base portion, and the plurality of cooling fins of the thermally conductive housing being disposed on the bottom wall of the base portion.
 5. The battery pack of claim 2, wherein the thermally conductive housing is constructed of aluminum.
 6. The battery pack of claim 1, wherein the first battery cell is disposed against a first side of the heat exchanger, the battery module further having a second battery cell disposed against the first side of the heat exchanger.
 7. The battery pack of claim 1, wherein the heat exchanger comprises first and second thermally conductive plates being coupled together and defining the first flow path portion extending therethrough; the first flow path portion having at least first and second flow path subportions extending through the first and second thermally conductive plates.
 8. The battery pack of claim 7, wherein the first battery cell being disposed against a first side of the first thermally conductive plate of the heat exchanger, the battery pack further comprising a second battery cell being disposed against the first side of the first thermally conductive plate of the heat exchanger.
 9. The battery pack of claim 7, wherein the first and second thermally conductive plates are constructed of aluminum.
 10. The battery pack of claim 1, wherein the electric fan is further disposed proximate to the outlet aperture of the battery pack housing
 11. A method for assembling a battery pack, comprising: providing a battery pack housing, a battery module, a thermally conductive housing, and an electric fan; the battery pack housing defining an interior region, the battery pack housing further having an inlet aperture and an outlet aperture communicating with the interior region; the battery module having a first battery cell, a heat exchanger, and first and second end plates; the first battery cell and the heat exchanger being disposed against one another, and being further disposed between the first and second end plates; the heat exchanger defining a first flow path portion therethrough; the first battery cell having a first end and a second end; the first end plate extending substantially parallel to a longitudinal axis of the battery module, the first end plate having a first end portion and a second end portion, the first end portion of the first end plate extending longitudinally past the first end of the first battery cell; the second end portion of the first end plate extending longitudinally past the second end of the first battery cell; the second end plate extending substantially parallel to the longitudinal axis of the battery module, the second end plate having a first end portion and a second end portion, the first end portion of the second end plate extending longitudinally past the first end of the first battery cell; the second end portion of the second end plate extending longitudinally past the second end of the first battery cell; disposing the battery module in the interior region of the battery pack housing proximate to the inlet aperture; disposing the thermally conductive housing in the interior region of the battery pack housing between the battery module and the outlet aperture of the battery pack housing; the thermally conductive housing defining a second flow path portion between the thermally conductive housing and the battery pack housing, the second flow path portion communicating with the first flow path portion; and disposing the electric fan in the interior region of the battery pack housing; the electric fan adapted to urge air to flow through the inlet aperture and through the first and second flow path portions and further through a portion of the electric fan and through the outlet aperture of the battery pack housing. 